The present invention relates to an electric rotary machine such as a turbine generator, and in particular to a cooling structure thereof.
As to ventilation cooling for a hermetic electric rotary machine, coolers are installed in a ventilation passage through which gas warmed after cooling a stator and a rotor is led into the cooler so as to cool the gas. In this installation method, it is general to arrange the coolers at positions which are left-right symmetric on the left and right sides, as disclosed in Japanese Laid-Open Patent Publication No. H5-161307. In the case of a single forward system, gas flows outward from the center part and through the coolers, and then flows through a fan for boosting up the gas so as to cool the rotor and the stator before it is returned into the coolers. Further, in the method of installing the coolers, as disclosed in this publication, the coolers are located above and away from the stator, being spaced from coil ends of the stator by means of a partition panel. By arranging the coolers at such positions, water produced through condensation within the coolers can be prevented from dropping onto the stator and the coil end of the stator.
However, the conventional technology stated in the Japanese Laid-Open Patent Publication No. H5-161307 does not concern those relating to the following problems.
First, it is required to aim at uniformly distributing the temperature in the axial direction in the case of a large capacity of an electric rotary machine, and accordingly, the axial lengths of the rotor and the stator become longer. Thus, there is such a problem that the volume of cooling air flowing into the ventilation cooling passage located in the axially center part is insufficient, and therefore, the temperature of the axially center part becomes higher than that of an axial end part.
An object of the present invention is to provide an electric rotary electric machine which can ensure the volume of cooling air flowing into the cooling air passage in the axial center part, and which can uniformly distribute the temperature in the axial direction.
To the end, according to the present invention, there is provided a rotary machine having internal machine gas coolers, in which a cooling air passage formed in each of the machine gas coolers, is divided into not less than two of passage parts in which streams in two opposite directions are created, partial zones located on radially outsides of a stator, and divided into not less than two of parts in the axial direction, and connection passages connecting the passage parts in the coolers are formed.